no dejagnu.h on Alpine Linux

[Bruno Haible]

Poke's configure.ac tests for Dejagnu this way:

  AC_CHECK_HEADERS([dejagnu.h])
  AM_CONDITIONAL([HAVE_DEJAGNU], [test "$ac_cv_header_dejagnu_h" = yes])

However, on Alpine Linux, the binary package 'dejagnu' does not contain a
<dejagnu.h> file (see the file list [1]). Hence HAVE_DEJAGNU evaluates to
false on these systems.

This way, I can't really run "make check" on my 5 Alpine Linux machines
(x86_64, x86, arm64, ppc64le, s390x).

dejagnu.h is documented [2].
Is it simply a packaging bug of Alpine Linux?
Should poke bundle dejagnu.h in the tarball?
Should Gnulib have a 'dejagnu' module that provides this .h file if not present?

Bruno

[1] 
https://pkgs.alpinelinux.org/contents?branch=v3.14&name=dejagnu&arch=x86_64&repo=main
[2] https://www.gnu.org/software/dejagnu/manual/C-unit-testing-API.html